A decade ago, the global financial crisis - the worst since the Great Depression, hit around the world. Now experts are warning another could be on its way.

"The global economy and the New Zealand economy does tend to run in a 10-year cycle, so statistically I think a lot of people are looking over their shoulder and wondering if it's the start of something ominous," economist Cameron Bagrie told Newshub.

Friday's problems for Apple are symptomatic of a wider concern about China.

"China's a very big economy so they don't just dish out ripples when the Chinese economy slows, they dish out waves," Mr Bagrie said.

He said China isn't alone - the US and European economies are also weakening. The reasons include what he calls a "dangerous cocktail" of trade wars between the US and China and a lack of economic leadership around the globe.

"What we're seeing globally - it's a moderation in growth as opposed to what you'd call a downturn, but certainly the warning signs are there and New Zealand needs to be careful."

So what does it mean for New Zealand? Catherine Beard, the executive director of Export NZ, said it's a concern.

"It will be a worry, China's such a massive economy, and they're our number one trade partner so any slowdown in China would be something we'd be concerned about," she told Newshub.

In 2017 China imported $4.1 billion worth of New Zealand's milk powder, butter and cheese, but Ms Beard said these are more insulated from economic slowdowns because high value foods tend to be one of the last things consumers skimp on.

However New Zealand's other big earners aren't safe.

"The education exporters are those who are trying to get overseas students to come and study here," Ms Beard said.

"They'll be watching very closely what's happening to the Chinese economy, and tourism's a big earner for New Zealand as well and a lot of those tourists are coming from China."

The saving grace for exporters of goods might be the Comprehensive and Progressive Agreement for Trans-Pacific Partnership trade deal, which has just taken effect.

It's opened up Mexico, Japan and Canada, giving Kiwi businesses tariff-free access to high income markets.